Abstract: A hybrid optical fiber integrates features of multimode optical fibers and single-mode optical fibers. The hybrid optical fiber possesses an optical core having a first core region and a second core region to provide improved optical mode coupling ratio for single-mode transmission while maintaining a broad bandwidth for multimode transmission. The hybrid optical fiber's optical core may optionally include a depressed trench positioned between the optical core's first core region and the optical core's second core region to reduce modal dispersion and to improve modal bandwidth during multimode transmissions.

Abstract: It is proposed a home optical data network formed of an optical fiber comprising an optical core and an optical cladding surrounding the optical core, the optical core having a refractive graded-index profile with a minimal refractive index n1 and a maximal refractive index n0, said optical fiber being such that it has a numerical aperture NA and an optical core radius a satisfying a criterion C of quality of optical communications defined by the following equation: C = NA - 0.02 × a where ? : NA = n 0 2 - n 1 2 = n 0 · 2 ? ? ? ? with ? ? ? = n 0 2 - n 1 2 2 ? n 0 2 , ? is the normalized refractive index difference, and in that said minimal and maximal refractive indexes n1, n0 and said optical core radius a are chosen such that NA>0.20, a>10 ?m and |C|<0.20.

Abstract: A hybrid optical fiber integrates features of multimode optical fibers and single-mode optical fibers. The hybrid optical fiber possesses an optical core having a first core region and a second core region to provide improved optical mode coupling ratio for single-mode transmission while maintaining a broad bandwidth for multimode transmission. The hybrid optical fiber's optical core may optionally include a depressed trench positioned between the optical core's first core region and the optical core's second core region to reduce modal dispersion and to improve modal bandwidth during multimode transmissions.

Abstract: It is proposed a home optical data network formed of an optical fiber comprising an optical core and an optical cladding surrounding the optical core, the optical core having a refractive graded-index profile with a minimal refractive index n1 and a maximal refractive index n0, said optical fiber being such that it has a numerical aperture NA and an optical core radius a satisfying a criterion C of quality of optical communications defined by the following equation: C = NA - 0.02 × a where ? : NA = n 0 2 - n 1 2 = n 0 · 2 ? ? ? ? with ? ? ? = n 0 2 - n 1 2 2 ? n 0 2 , ? is the normalized refractive index difference, and in that said minimal and maximal refractive indexes n1, n0 and said optical core radius a are chosen such that NA>0.20, a>10 ?m and |C|<0.20.

Abstract: It is proposed an optical fiber including an optical core and an optical cladding surrounding the optical core. The optical core has a refractive graded-index profile with a minimal refractive index n1 and a maximal refractive index n0. The optical fiber has a numerical aperture NA and an optical core radius ? satisfying a criterion C of quality of optical communications defined by the following equation: C=NA?0.02×a where: NA=?{square root over (n02?n12)}=n0·?{square root over (2?)} with ? = n 0 2 - n 1 2 2 ? ? n 0 2 , ? is the normalized refractive index difference. The minimal and maximal refractive indexes n1, n0 and the optical core radius a are chosen such that NA>0.20, a>10 ?m and |C|<0.20.

Abstract: A hybrid optical fiber integrates features of multimode optical fibers and single-mode optical fibers. The hybrid optical fiber possesses an optical core having a first core region and a second core region to provide improved optical mode coupling ratio for single-mode transmission while maintaining a broad bandwidth for multimode transmission. The hybrid optical fiber's optical core may optionally include a depressed trench positioned between the optical core's first core region and the optical core's second core region to reduce modal dispersion and to improve modal bandwidth during multimode transmissions.

Abstract: It is proposed an optical fiber including an optical core and an optical cladding surrounding the optical core. The optical core has a refractive graded-index profile with a minimal refractive index n1 and a maximal refractive index n0. The optical fiber has a numerical aperture NA and an optical core radius a satisfying a criterion C of quality of optical communications defined by the following equation: C=NA?0.02×a where: NA=?{square root over (n02?n12)}=n0·?{square root over (2?)} with ? = n 0 2 - n 1 2 2 ? ? n 0 2 , ? is the normalized refractive index difference. The minimal and maximal refractive indexes n1, n0 and the optical core radius a are chosen such that NA>0.20, a>10 ?m and |C|<0.20.

Abstract: A hybrid optical fiber integrates features of multimode optical fibers and single-mode optical fibers. The hybrid optical fiber possesses an optical core having a first core region and a second core region to provide improved optical mode coupling ratio for single-mode transmission while maintaining a broad bandwidth for multimode transmission. The hybrid optical fiber's optical core may optionally include a depressed trench positioned between the optical core's first core region and the optical core's second core region to reduce modal dispersion and to improve modal bandwidth during multimode transmissions.

Abstract: An in-fiber mode converter comprises fiber portions (10) constituting an input microlens, a fiber portion (20) constituting a phase shifting region adapted to convert a propagation mode of an optical signal into another propagation mode, and fiber portions (30) constituting an output microlens. The fiber portions are spliced, the converter is compact and losses are minimized relative to mode conversion in free space.

Abstract: An in-fiber mode converter comprises fiber portions (10) constituting an input microlens, a fiber portion (20) constituting a phase shifting region adapted to convert a propagation mode of an optical signal into another propagation mode, and fiber portions (30) constituting an output microlens. The fiber portions are spliced, the converter is compact and losses are minimized relative to mode conversion in free space.

Abstract: An optical module for chromatic dispersion compensation comprises an optical fiber wound so as to present a variable radius of curvature. The fiber has an index profile such that it has, for the main propagation mode, a negative dispersion value having a minimum at a given wavelength in a given spectral band. The value and the spectral position of the dispersion minimum vary with the radius of curvature of the fiber. The module allows the introduction of a large chromatic dispersion compensation value overall of a given spectral band, as well as compensation corrections for specific wavelengths inside the given spectral band.

Abstract: The invention relates to an optical fiber presenting a core, cladding, and a grating written by irradiation and coupling at least one light mode into the cladding so that it is dissipated therein. The invention proposes causing the mean index to vary progressively along the grating, at least at the ends of the grating. The progressive variation in mean index or in the amplitude of index modulation for writing the grating serves to limit insertion losses to the filter formed by the grating. Analogously, in a written-in grating, the invention provides the equivalent of progressively varying the core size of the fiber for interconnecting two optical fibers presenting different core diameters. The invention is applicable in particular to gain-equalizing filters in WDM transmission systems.

Abstract: The fibre is adapted to compensation of the chromatic dispersion and chromatic dispersion slope of an optical fibre with negative chromatic dispersion. It has, in a propagation mode other than the fundamental mode, a positive chromatic dispersion and a negative chromatic dispersion slope. The fibre can be used in compensation dispersion modules or as line fibre, in transmission systems using line fibre with negative chromatic dispersion.

Abstract: The fiber is adapted to compensation of the chromatic dispersion and chromatic dispersion slope of an optical fiber with negative chromatic dispersion. It has, in a propagation mode other than the fundamental mode, a positive chromatic dispersion and a negative chromatic dispersion slope. The fiber can be used in compensation dispersion modules or as line fiber, in transmission systems using line fiber with negative chromatic dispersion.

Abstract: An optical module for chromatic dispersion compensation comprises an optical fiber wound so as to present a variable radius of curvature. The fiber has an index profile such that it has, for the main propagation mode, a negative dispersion value having a minimum at a given wavelength in a given spectral band. The value and the spectral position of the dispersion minimum vary with the radius of curvature of the fiber. The module allows the introduction of a large chromatic dispersion compensation value overall of a given spectral band, as well as compensation corrections for specific wavelengths inside the given spectral band.

Abstract: The object of the present invention is to design a photonic crystal fiber with high birefringence property such to preserve the polarization of optical signals transmitted through such fiber without implying to high manufacturing cost. For that a photonic crystal fiber is designed having at least the inner rows of the used longitudinal holes surrounding its guiding core following a parallelogram shape arrangement. This leads to a photonic crystal with an at most two fold rotational symmetry about a longitudinal symmetry. It is a particularly advantageous way to introduce a high birefringence which will guarantee to retain the polarisation of the transmitted optical signals.

Abstract: The fibre is adapted to compensation of the chromatic dispersion and chromatic dispersion slope of an optical fibre with negative chromatic dispersion. It has, in a propagation mode other than the fundamental mode, a positive chromatic dispersion and a negative chromatic dispersion slope.

Abstract: The invention relates to polarization mode dispersion; writing index variations in a grating written in an optical fiber generates polarization mode dispersion. The invention proposes to compensate this polarization mode dispersion by mechanical curvature of the fiber. The invention provides a simple method of compensating polarization mode dispersion effectively and improving the performance of a grating written in a fiber; it applies in particular to Bragg gratings.

Abstract: The invention relates to an optical fiber presenting a core, cladding, and a grating written by irradiation and coupling at least one light mode into the cladding so that it is dissipated therein. The invention proposes causing the mean index to vary progressively along the grating, at least at the ends of the grating. The progressive variation in mean index or in the amplitude of index modulation for writing the grating serves to limit insertion losses to the filter formed by the grating. Analogously, in a written-in grating, the invention provides the equivalent of progressively varying the core size of the fiber for interconnecting two optical fibers presenting different core diameters. The invention is applicable in particular to gain-equalizing filters in WDM transmission systems.

Abstract: The line optical fiber of the system is single-mode and has a very large effective mode area accompanied by high chromatic dispersion and/or a steep spectrum gradient of said dispersion. Compensation means are associated with said fiber so as to compensate at least a major portion of said dispersion and/or of said gradient. They are integrated into repeater units distributed along the transmission line. The invention applies to telecommunications.